Break In Secrets

[irokin]

http://www.mototuneusa.com/break_in_secrets.htm

 

discuss...

[TRD ke70]

very interesting, but some of the owners manuals do say give wide open thottle while running the engine in,now wide open throttle isn't reving the shit out of the engine, they also say don't labour the engine.

 

i think he's right, but i don't think the idea is new, i'd be interested to here other mechanic's or engine builders ideas.

[Xany]

thats basically how my brother and i broke in my engine......and its still running very nice.....except for the stem seal problem.....which will be getting fixed very shortly....after that i don't think i'll have anymore dramas with it.

 

in the long run if you want your engine to last.....i'd run it in like this....

 

my home area is nice and hilly, so the car had a chance to "load up" on full throttle.

[Banjo]

I'm actually fascinated by this subject, and tend to agree completely with the theory that initial bedding in of a new engine is the key to a successful rebuild.

 

This story is quite old, but is in the same vein. It comes from Mastang Sally's Land Rover Pages, which is a very good read. Many of you have probably visited the site, but for those newbies, please read the following and don't scoff ! Stranger things happen with motor cars !

The Universal Cleanser

 

This one was told to me by the proprietor of a Mackay automotive engineering works, a man well respected in the trade. In the late 1960's he was an apprentice motor mechanic with the local distributors of British and European cars. The first of the six cylinder 109 Land Rovers in the district had been sold by them. The new owners soon brought them back, complaining bitterly about blue smoke and horrendous oil consumption. Cylinder heads were lifted on a couple of them revealing glazed bores and the only remedy the firm could think of was a light de-glazing hone and new rings.

The more of these sixes they sold, the more it began to look like an epidemic. Rover Australia were contacted and it seems that it was an Australia wide epidemic of near-new, smoky, oil guzzling 2.6 litre Land Rovers.

Eventually the solution came in the form of a technical bulletin from Rover HQ. There was something wrong with the bore finish on these engines and if they were treated gently, as owners of new cars tend to do, the rings would never bed in and the bores would glaze. Owners should be instructed to give them plenty of welly in the first few hundred miles.

The official fix for those vehicles already affected was as follows:-

Remove the aircleaner. Start engine and set to a fast 1500 rpm idle.Take a tablespoon full of Bon Ami, a popular household cleanser and slowly tap the powder into the carburettor throat over a period of fifteen minutes. Put everything back in place and take the vehicle for a brisk test drive.

The bulletin was most insistent that it should be Bon Ami cleanser. Ajax or Jif would not do.

My informant swears that this story is 100% true and that the fix did, in fact, work exactly as advertised.

 

Postscript:

David Walworth and Michelle Peterson of St.Croix in the Virgin Islands write:-

Hi Steve, liked the story about the use of Bon-Ami cleanser to break in the rings on an engine. Turns out, this fellow from Washington State was visiting us down here in St. Croix who had a story about the use of Bon-Ami in engine rebuilds. Well, this guy Jeff is a Harley-Davidson motorcycle nut. A mechanic told him to wipe down the bores with Bon-Ami just before assembling the engine on his motorcycle. Don't use copious amounts, but don't wipe away the residue, either. There was also some advice about starting it, let it run for 30 seconds, shut off. Then let cool, restart, run for 2 minutes, etc. Well, Jeff says that engine was the longest running engine of any of the bikes he had owned up to that time. Same thing, it had to be Bon-Ami. I told Jeff the story about the Australian 6 cylinder Land Rovers in return. So, who knows? Maybe I should pour a teaspoon down the throat of my IIa diesel and see if it helps with the smoke and oil consumption. Couldn't make it much worse!

 

Cheers, Dave

 

:D

[irokin]

It makes sense to me in theory...Just wanted to hear other peoples opinions before I run my several thousand dollar fresh SR20 in using that method. So far I havent heard any bad reports from that method.

[Super Jamie]

this was one of the few webpages i paid attention to when looking for ideas on how to break in my motor, the street driving section is good advice

 

doing full throttle runs from low rpm to mid-high rpm (not redline) is a great way to get your rings to suck out and wear properly against the bores. people reckon something like 90% of your ring sealing is going to be done in the first couple of hundred km after building a motor, the rest will slowly happen over the next few thousand

 

oil surface bushings such as your crank, rod and cam bearings will be worn in within the first half hour

 

another good tip i got is to temperature cycle the motor, gradually building up time. run it for 10 minutes, let it cool down totally. run it for 20 minutes, let it cool down totally, run it for 30 minutes, let it cool down totally. and so on. an engine doesn't really wear when it's cold (20C) and it doesn't really wear when it's hot (90C), it wears when it's in its warmup period (30C to 80C)

 

oil is also important. i ran pennzoil running in oil for the first few hundred km, which has alot of graphite content in it, which helps lubricate the tight metal parts as they rub in against each other. after that, i changed to a straight weight (30w) mineral oil for the next few thousand km, and i renewed it twice. one day, the motor just had a HEAP more power, everything had finally bedded in and it was run in. then i swapped to a 5w synthetic, but didn't like the tappet noise, so changed to a thicker 15w. at every change, i used a new genuine filter

 

before your first start, wind the engine over with no spark to get oil pressure up. you'll probably flatten a battery or two to do this, that's normal. for the first time (and first time ONLY) warm the engine up to operating temperature without driving it, as you warm it up, hold and cycle the revs. 2 minutes at 2000rpm, 2 minutes at 2500rpm, 2 minutes at 3000rpm. continue this to half your redline. then let it cool down totally

 

never leave any engine (even an old one) sitting more than a few minutes to warm up, drive it, even if it's just around the block. the oil circulation will help the engine warm up evenly with more uniform heat dispersal, and it will wear alot less as it settles up to operating temperature. it also gives the engine more oil pressure than idling, and that's a good thing

 

i gradually increased my rev ceiling. 6000rpm on the first day, 7000rpm on the second day, 8000rpm on the third day, and by that point it was time to get rid of the running in oil. probably not good to rev an engine hard on running in oil, it's pretty thin and doesn't lubricate bearing surfaces so well under such extreme conditions

 

if you have a running fuel supply (such as a stock carburettor) leave it stock until the engine is run in. there's no point upgrading and tuning something on a motor whose conditions are still constantly changing. nor is there much point cranking a fresh motor needlessly whilst you get a beginning idle worked out

 

i don't really believe in running an engine in on the dyno. acutally i think dynos are a good way to f@$k engines because most of them (or more accurately, the operators) don't load the driveline properly, and instead of being a good torque ability simulation, they end up being halfway between normal driving and free-revving. would you sit on your driveway and slowly freerev your engine to its redline? thought not

 

lastly, you're not going to run an engine in overnight. most of it happens within 500km, the rest takes at least a few thousand. mine took over 6

 

 

NOW

 

this is all good and well for an old 4k, these are high ring tension motors with old designs. a new car engine is totally different, they have very low tension rings and realistically aren't designed to last more than a couple of hundred thousand km. not like a corolla which you can do half a million clicks in and it still runs every day without fail. most new cars have already done a full power run in the factory on their dyno (to test the engine isn't a lemon), and been driven on and off a car trailer and around a dealership for at least a few km. so babying it isn't going to do anything helpful

 

if i bought a brand new car, i'd drive it out the dealership, warm it up around town, get out to a long stretch of road and leave it in 3rd or 4th and bury my foot till i'm doing well over 100km/h (yeah yeah breakin the law). then just drive it like you would any other car

 

the old mechanic who told me what i expressed above about dynos used to have a good saying for how he treats his engines - "you wreck em if you drive lightly, and you wreck em if you flog em. so i just lightly flog em" :D

 

your opinion may vary, but that's what i've ascertained from reading alot of peoples' running in stories, and talking to alot of people who do it all the time

Edited April 7, 2005 by Super Jamie

[Medicine_Man]

Just don't go mad revving the guts out of it and snap a ring, nothing wrong with giving it some stick here and there, you have to alternate your driving style and let those rings bed in..

[Redwarf]

I'm a run-it-in-like-your-going-to-drive-it person. The Pajero was driven like a daily driver. One Dwarf engine did 30 laps of Calder to run it in, and it lasted over 5 years. Current engine was driven to Willowbank, then did an Autocross to settle it. Admittedly I didn't take it over 6 or at the most 7K. It still goes fine.

[Super Jamie]

and you don't really expect a performance engine to last over $150,000km anyway :D